The present invention relates to energy-conserving blinds for use in the windows of a building, and more particularly, to improved construction of such blinds to reduce the heat loss or gain produced by the windows and to provide for minimum air flow between slats when the blinds are closed. As used herein, the term "window" applies to any glazed sunlight admitting opening.
The solar energy transmitted through large south-facing windows can provide a substantial contribution toward the heating requirements of residences and buildings. However, these same windows (as well as all glazed units) give rise to large heat losses during heating seasons and heat input during cooling seasons. The heat transfer is reduced approximately 1/2 through the use of doubly glazed units. Even so, the heat transfer is at least twice that of acceptably insulated wall systems. A further problem of large windows arises due to glare and to the fading of fabrics and furniture exposed to the sun.
Common partial solution to these problems has been the use of various types of blinds and drapes. Unfortunately, the use of such covering of the windows negates the potential solar input benefit. The covering at night does provide some insulation due to the multiple air layers. Typical of the coverings known in the art are drapes with metalized backing, roll-up shades and venetian blinds. The latter may have a reflective outer surface, and may be mounted between window layers as well as on the room side of the windows. Special screening is also available to install exterior to the window.
It is an object of the present invention to provide improved window blinds that not only provide reflection of sunlight upward toward the ceiling of a room during the daylight hours but also provide insulation for the room when they are closed for reducing the heat loss or gain produced by the windows.
It is another object of the present invention to provide reflective insulating blinds for windows that also provide a minimum air flow between th slats thereof when the blinds are closed.
Other objects, advantages and novel features of the invention will become apparent to those skilled in the art upon examination of the following detailed description of a preferred embodiment of the invention and the accompanying drawings.